1. Field of the Invention
The present invention relates to an apparatus and method of cultivating a plant using a subirrigating method and, more particularly, to an apparatus and method of cultivating a plant using a subirrigating method, which continuously provides the root of the plant with a nutritive solution and air, thereby maintaining their growth environments in optimum conditions.
2. Discussion of Related Art
In general, methods of cultivating ornamental plants or edible plants includes a culture medium cultivation method of planting and growing the plants in culture medium and a nutriculture method of providing the plants with a nutritive solution mixed with nutrients required for the growth of plants. The culture medium cultivation method uses general soil or artificial culture medium. Conventional methods of planting do not rapidly grow plants because their roots are not actively provided with moisture, nutritive substances and air. Accordingly, the nutriculture method of supplying the nutritive solution mixed with the nutritive substances needed for the growth of the plant is employed when a forcing culture or special culture is required. The nutriculture method includes a water culture which grows the plant, their roots directly being in contact with the nutritive solution, and a culture medium culture which plants the plant in the culture medium to be supported. In the culture medium culture, a method for supplying the nutritive solution required for the growth of the plant includes a spray irrigation of spraying water down on the leaves of the plant, a dipping method of dropping water only on the root of the plant, and a subirrigation of supplying water to the plant from the bottom of them.
In conventional spray irrigation, a portion of constituents included in the nutritive solution may affect the leaves of the plant when it comes into contact with them. Furthermore, this method must precisely control the period of supply of water required for the roots. Drip irrigation requires equipment for dropping the nutritive solution only on the root of the plant, resulting in the demand for an additional expense for the equipment. This method also has the inconvenience of precisely controlling the time of supplying water required for the root of the plant.
The subirrigating method which provides water only to the root of the plant when it is required is effective and practical because it does not need lots of equipment and allows the roots to breathe. The root of the plant should be provided with air together with water, to be able to breathe, thereby being grown normally or even rapidly. Accordingly, it is very important that the roots are supplied with sufficient air together with moisture in cultivating the plant with the nutriculture using the subirrigating method. As described above, to cultivate the plant using the subirrigation requires various environments. These environments cannot be obtained when an artificial culture medium used for the general nutriculture is employed. Thus, the subirrigating method cannot be effectively applied.
Conventionally, the plant is cultivated, being planted in the artificial culture medium filled in a container having a predetermined shape, such as planting pot or flowerpot. When it is required that the seed or seedling of the plant grows in the artificial culture medium and then they are transferred to be planted in other places, the artificial culture medium should be changed because it does not have a predetermined shape. The conventional artificial culture medium is in the bulk state as the general soil, or easily crushed even if it has a specific shape. Thus, the artificial culture medium in which the plant is planted cannot be moved. Accordingly, in case of a flower garden which produces flowering plants, the seeds or seedlings of the flowering plants should be grown in a producing district from the beginning. Thus, the flowering plants cannot be produced from the producing district until their seeds or seedlings are completely grown. This problem is caused by difficulty in moving the culture medium in which the grown flowering plants are planted to other places.
Meanwhile, the plant growth needs sufficient air as well as moisture and nutrients. That is, the subirrigating method requires time for the roots to breathe. The roots may be damaged when they do not breathe for several minutes in an extreme case although it depends on the season, temperature and kind of plant. Accordingly, the nutritive solution and air must be alternately supplied to the root of the plant with the precise supplying time in order to effectively cultivate the plant using the subirrigation.
For this, there has been proposed a method constructed in such a manner that a space through which the nutritive solution is supplied is prepared under a planting pot and the nutritive solution is provided or discharged through the space with a predetermined period of time, or planting pots where plants are planted are arranged on the nutritive solution filled in a container at a predetermined interval and a wick having a good moisture absorptiveness is inserted into the lower part of each planting pot, the lower part of the wick being dipped in the nutritive solution, to absorb the nutritive solution, thereby supplying it to the culture medium in the planting pots. This method can let the plants absorb the moisture and nutrients whenever they need them because the nutritive solution is being provided all the time. However, it cannot completely solve the problem of supplying air into the culture medium, and requires a structure for setting the planting pots into which the wicks are inserted on the nutritive solution container. In case that various plants are needed to be simultaneously planted, especially, a special structure for setting the planting pots is required.
Temperature is an essential element in the growth environment of a plant. In most cases, the plant is cultivated in a greenhouse when the temperature is lower, for example, in the winter time. Because the temperature of the root is very important in the growth of a plant, a general heating method sets the temperature of the greenhouse to the temperature of the root, required for the plant growth. Accordingly, this needs lots of expense for heating the entire greenhouse. To solve this problem, it is preferable that only the root temperature is raised while the temperature inside the greenhouse is appropriately maintained.
When plants are cultivated using a nutrient solution, the temperature of the nutrient solution increases when the temperature rises in the summer, reducing the dissolved oxygen contained in the nutrient solution. Furthermore, the respiration of the roots becomes prosperous according to high temperature due to intensive sunshine of the summer time. When the dissolved oxygen contained in the nutrient solution is insufficient, the oxygen absorbed by the root is reduced, resulting in poor growth of the root. This fades or suffocates the plant, harming its growth. In case of roses, for example, it is impossible to produce high quality roses in the summer time because of the aforementioned phenomenon. To solve this problem, there has been proposed a method of mingling the nutrient solution with hydrogen peroxide mixed with distilled water so as to provide the nutrient solution with a large amount of oxygen. However, this method is very complicated process and is not suitable for large-scale farms.
In general, the respiration of the root of a plant increases several times when the temperature rises by 10xc2x0 C., and the dissolved oxygen contained in the nutritive solution is considerably reduced with increasing temperature. This results in deficiency of oxygen in the root. Specifically, the plant growth becomes remarkably poor when the dissolved oxygen at the root is less than 2 ppm, and the plant stops its growth and its root is blighted when it becomes lower than 0.5 ppm, deteriorating the productivity.
When a street or the interior of a building is decorated with flowering plants or foliage plants, planting pots containing them may be placed above the ground, having a considerable distance therebetween, or they may be placed high in multistage. In this case, it is difficult to employ the subirrigation which supplies water toward the plant root. To solve this problem, there has been used an apparatus of supplying water to planting pots placed high above a container source containing the nutritive solution using a power water pump. However, this apparatus requires a power source for the water pump and also needs additional means, such as a water level sensor, for providing an exact amount of water to the water pump all the time according to the characteristics of plants. Moreover, even if this sensor is employed, it is still difficult to precisely set the period of time during which the root of the plant can breathe while the water required for the plant growth is supplied.
Instead of using the water pump, there may be considered a method of supplying water to a plant placed high above the source of water using a wick such as cotton or sponge. However, there are limitations in guiding water from a lower place to a upper place using the cotton or sponge. This is because that water can be actually guided up to the height of 10 centimeter when the cotton or sponge is used. To effectively provide the plant, placed above the source of water by 1 meter to several meters, with an appropriate amount of water, the method of using the power water pump is employed. However, this method cannot accompany the cultivating method which provides the culture medium with air as well as nutritive solution continuously.
Accordingly, the present invention is directed to an apparatus and method of cultivating a plant using a subirrigating method that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a plant cultivating apparatus which cultivates a plant using artificial culture medium having a good porosity and drainage, the artificial culture medium being shaped in a predetermined form to be able to transfer the plant which has been grown therein to other places, the apparatus including a culture medium cell through which a nutritive solution and air can freely pass.
Another object of the present invention is to provide a plant cultivating apparatus which allows sufficient amount of air to pass through the root of a plant planted in the culture medium cell so as to simultaneously supply the nutritive solution and air to the root without cease, thereby rapidly growing the plant.
A still another object of the present invention is to provide a plant cultivating apparatus which is able to heat or cool the root of a plant as needed, and forcibly supply air required for the root to accelerate the rapid growth of the plant.
A further object of the present invention is to provide a plant cultivating apparatus which automatically supplies the nutritive solution to planting pots arranged in multistage or placed above a container containing the nutritive solution required for the plant growth, having a predetermined distance therebetween.
Another object of the present invention is to provide a plant cultivating apparatus which continuously supplies the nutritive solution and air to the root of the plant planted in the culture medium without cease, to allow the plant to grow in an optimum state.
To accomplish the objects of the present invention, there is provided a plant cultivating apparatus using a subirrigating method which supplies moisture and nutrients required for the growth of a plant from the bottom of a culture medium in which the plant is planted, the apparatus including a culture medium cell constructed in such a manner that the culture medium is composed of artificial culture medium made of coconut peat or perlite, the artificial culture medium being packed in an inner packing material first and then packed in an outer packing material, the inner packing material being made of a material through which moisture and air can smoothly pass, the outer packing material being made of a material having a predetermined degree of strength to maintain the culture medium contained therein in a predetermined shape, the outer packing material having a plurality of holes through which water passes at its lower part, the inner and outer packing materials having cuts for planting seeds or seedlings at their tops.
The culture medium cell may be used without employing any additional device, or used being contained in a planting pot according to the present invention, to thereby supply a nutritive solution and air to the root of a plant continuously. This maintains plant growth environments in which the root of the plant is not under the stress due to dryness or overhumidity, promoting the rapid growth of the plant. The planting pot according to the present invention has a plurality of holes through which the nutritive solution and air pass.
The locations where the holes are placed and the number of them depend on the size of the planting pot. In case of a small-size planting pot, for example, the holes are formed at the overall side wall of the planting pot. In case of a large-size planting pot, the holes are formed at a portion of the planting pot, ranging from its bottom to a level higher than the position corresponding to one third of its volume. The planting pot may be replaced by a vinyl basket having a plurality of holes at its side. It is preferable to decide the planting pot having the holes formed at the overall side thereof or the planting pot having the holes formed at the lower part of the side thereof, according as sufficient capillary action can occur or not in the culture medium cell contained in the planting pot.
The planting pot or culture medium cell is dipped in a nutritive solution container filled with a nutritive solution, only one third of the planting pot or culture medium cell being soaked therein, to allow the nutritive solution contained in the container to be continuously supplied to the root of the plant planted in the culture medium cell, simultaneously, to allow air to be provided to the root through the portion which is not dipped in the nutritive solution. Accordingly, the root of the plant can continuously absorb the nutritive solution and breathe without accepting the stress due to dryness or overhumidity, being maintained in the optimum growth environment, resulting in the rapid growth of the plant.
A cooling/heating pipe is placed at the lower portion of the culture medium cell contained in the planting pot to supply air to the root of the plant when large amount of air is required in the summer. Furthermore, the root of the plant can be forcibly cooled or heated using the temperature of the air provided through the cooling/heating pipe. Accordingly, the root of the plant can breathe normally even when the temperature is excessively high or low, and the temperature of the root can be controlled to be suitable for the growth, maintaining the optimum plant growth state.
Meanwhile, in case that the planting pots are placed above the nutritive solution container, having a considerable distance therebetween, or arranged in multistage, a nutritive solution supply unit for automatically supplying the solution may be set between the planting pots and nutritive solution container. The nutritive solution supply unit consists of a tube in which a high-density moisture absorbing material, and a moisture supplying device constructed in such a manner that a spiral pipe winds round the tube, the spiral pipe being filled with a high-density moisture absorbing material.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.